Limestone mass transfer model

Limestone (CaCC>3) dissolution is an important phenomenon in stack gas desulfurization processes using limestone slurry to absorb SC>2 and produce CaSC>3/CaS04 waste solids (1). The rate of dissolution directly determines the need for excess limestone and interacts strongly with SC>2 removal and scale-free operation in the absorber. There is a need to know the dependence of dissolution rates on both solution composition and the type and grind of limestone. This paper presents a mass transfer model and... 

Limestone dissolution in throwaway scrubbing can be modeled by mass transfer. The mass transfer model accurately predicts effects of pH, Pcc>2> temperature, and buffers. For particles less than 10-20 pm, the mass transfer coefficient can be obtained by assuming a sphere in an infinite stagnant medium. This model underpredicts the absolute dissolution rate by a factor of 1.88, probably because it neglects agitation and actual particle shape. 

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